diff options
Diffstat (limited to 'arch/x86/include/asm/tsc.h')
-rw-r--r-- | arch/x86/include/asm/tsc.h | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h new file mode 100644 index 000000000000..38ae163cc91b --- /dev/null +++ b/arch/x86/include/asm/tsc.h @@ -0,0 +1,62 @@ +/* + * x86 TSC related functions + */ +#ifndef _ASM_X86_TSC_H +#define _ASM_X86_TSC_H + +#include <asm/processor.h> + +#define NS_SCALE 10 /* 2^10, carefully chosen */ +#define US_SCALE 32 /* 2^32, arbitralrily chosen */ + +/* + * Standard way to access the cycle counter. + */ +typedef unsigned long long cycles_t; + +extern unsigned int cpu_khz; +extern unsigned int tsc_khz; + +extern void disable_TSC(void); + +static inline cycles_t get_cycles(void) +{ + unsigned long long ret = 0; + +#ifndef CONFIG_X86_TSC + if (!cpu_has_tsc) + return 0; +#endif + rdtscll(ret); + + return ret; +} + +static __always_inline cycles_t vget_cycles(void) +{ + /* + * We only do VDSOs on TSC capable CPUs, so this shouldnt + * access boot_cpu_data (which is not VDSO-safe): + */ +#ifndef CONFIG_X86_TSC + if (!cpu_has_tsc) + return 0; +#endif + return (cycles_t)__native_read_tsc(); +} + +extern void tsc_init(void); +extern void mark_tsc_unstable(char *reason); +extern int unsynchronized_tsc(void); +int check_tsc_unstable(void); + +/* + * Boot-time check whether the TSCs are synchronized across + * all CPUs/cores: + */ +extern void check_tsc_sync_source(int cpu); +extern void check_tsc_sync_target(void); + +extern int notsc_setup(char *); + +#endif /* _ASM_X86_TSC_H */ |